Call to web services fails within a Windows Service

We have a windows service that collects (phone) call records from a local database and consumes a web service to hosted at a remote server and sends call records. The windows service is running successfull in some other machines but in one of the machine
it throws an error saying:

There was no endpoint listening at http://domain-name/internal/CallLogService.asmx that could accept the message. This is often caused by an incorrect address or SOAP action. See InnerException, if present, for more details.

When I type the URI of web service in a browser at the client machine it works just fine. I can also check the definition of wsdl associated with the web service by pasting ?wsdl to the URI.

But I am totally puzzled by the fact that the windows service fails to consume the web service. Can someone point me to any direction to a resolution?

Re: Call to web services fails within a Windows Service

The solution worked fine for some time but came back again. What do you think I should look into? I am using a Windows 2003 server running IIS 6. The IIS runs an FTP site which I disabled for some time, but that didn't solve the endpoint issue.